1. Technical Field
The present invention relates to an audio signal processing system including a plurality of signal processing units and a control unit for controlling the signal processing units.
2. Related Art
Conventionally, a mixer is well known which adjusts levels and frequency characteristics of audio signals output from a large number of microphones or electric or electronic musical instruments or the like, then mixes the audio signals into several mixing groups, and transmits the mixing groups to a power amplifier. As this mixer, there is known a mixing system including a console section and an engine section connected to the console section through a communication line. In general, in the mixer, the console section is installed in an area of audience seats apart from a stage or in a mixer room provided behind the audience seats, and the engine section connected to the console section is provided in the vicinity of the stage. An operator operating the mixing console operates various panel operating pieces provided on the mixing console to adjust the volume and tone of each audio signal of an instrumental sound or a singing voice such that the resultant signal most properly expresses the musical performance. The engine section has a function for processing audio signals and has a plurality of microphone/line input channels as input signal systems. The engine section programs and mixes the input signal systems, and outputs a plurality of output channels serving as output signal systems.
In general, signals on the input channels of the input signal systems are amplified by a head amplifier and then output to a mixing processing section. Then, the mixing processing section adjusts the frequency characteristics and levels of the amplified signals on the respective input channels and mixes these signals in a programmed combination. Then, the resulting mixed signals are each set by an output fader to a desired output level and are output to one of the output channels.
In the conventional mixing system in which the communication line is connected between the engine section and the console section, the engine section for performing a mixing process may be installed in the vicinity of the stage and the console section may be installed in the area of the audience seats, such that a mixing operation may be performed while checking sound being listened to by the audience. Moreover, since microphone/line signals are input to the engine section for the mixing process installed in the vicinity of the stage, its cables can be easily laid or handled. Such a mixing system is disclosed for example in JP-A-2002-304173.
In the conventional mixing system, one engine section is connected to the console section. However, there has been proposed an audio signal processing system such as the mixing system in which a plurality of signal processing units for processing audio signals are connected to a transmission line, and a control unit connected to the transmission line controls the plurality of signal processing units. In this audio signal processing system, audio signals can be processed while increasing the desired number of channels by connecting the plurality of signal processing units to the transmission line even if the number of channels being processed in one signal processing unit is limited. The control unit performs an operation for setting parameters of each channel or the like in each signal processing unit. At this time, an operation screen is displayed on a display part of the control unit. On the operation screen, the operation for setting the parameters of each channel or the like in each signal processing unit is performed. When this operation is performed, a signal processing unit serving as an operation target needs to be specified. However, since the same operation screen is rendered commonly for any signal processing unit selected as a current operation target, the signal processing unit selected as the current operation target would be identified by reading character string information of a name, a number, or the like of the signal processing unit rendered on an upper or lower part of the operation screen.
However, a character string displayed on the operation screen should be carefully checked to specify the signal processing unit selected as the current operation target. However, there is a problem in that the character string may not easily specify the operation target since the character string is not a conspicuous indication.